如何修剪数组中每个键的最后两个字符？

This is my array (input):

$value = array("jan01" => "01", "feb02" => "02", "mar03" => "03", "apr04" => "04");

I am using this code to get the array keys:

implode(" ", array_map("ucwords", array_keys($value)));

Now my problem is I want to get all keys by triming the last two characters of each key.

How can I change/modify my code, so that it trim's the last two characters of each key?

EDIT:

I also want to skip first 3 keys, means I don't want the first 3 keys to be trimmed.

I think this should work for you:

Just take the substr() from your key and then use ucwords() on it.

implode(" ",array_map(function($v){
    return ucwords(substr($v, 0, -2));
},array_keys($value)));

EDIT:

AS from your updated question you don't want to take the substr from the first 3 elements. So just use a counter variable, e.g.

$counter = 1;
echo implode(" ", array_map(function($v)use(&$counter){
    if($counter++ > 3)
        return ucwords(substr($v, 0, -2));
    return ucwords($v);
},array_keys($value)));

Here's something for undetermined array depth.

$arr = your array;
$trimmed_values = array();

array_walk_recursive($arr, function($key, $value) use (&$trimmed_values)
{
    $trimmed_values[] = substr($key, 0, -2);
});

This won't work if you're not using PHP 5.3+ as lower versions don't have anonymous functions.